A sewing installation for producing a succession of buttonholes in a fabric workpiece is known, for example, from German Pat. No. 1,086,980. In this case, the workpieces are successively engaged by a tensioning clamping frame and are advanced stepwise with respect to a stationary stitch-group or buttonhole sewing machine. In the rest position between advances of the frame, the two buttonhole stitch beads and the endlocking portions of the buttonhole are stitched and subsequently the fabric is cut through between the beads of stitching.
The sewing of the first buttonhole on each fabric piece takes place at the same end of the piece so that, after completion of the displacement of the frame past the sewing machine for the production of the row of buttonholes, the frame is returned to its original position for the next operating cycle with a new fabric. The return movement of the frame is an unproductive period and limits the output of the machine. The capacity of modern stitch group sewing machines is thus not fully utilized.